Technical Field
The present invention relates to detergent compositions comprising an enzyme and a bleaching compound. In particular the present invention relates to such a detergent composition wherein the bleaching compound and the enzyme are located in different regions of the composition.
Background
It is well known that detergent compositions comprising both an enzyme and a bleaching compound typically suffer from stability problems of the enzyme because of the detrimental effect thereon of the bleaching compound. This results in either 1) loss of performance of the enzyme and hence the detergent compound, and/or 2) the need to include increased levels of the enzyme in the detergent composition so increasing cost.
It has been attempted to address the above problem by separating the bleaching compound and the enzyme into different regions in order to reduce the possibility that the bleach will adversely affect the stability of the enzyme and products of this type are already commercially available.
Simply separating these ingredients into different regions has not been found to sufficiently address the instability problem of the enzyme as some reaction still takes place between the bleaching compound and the enzyme at the interface of the regions and thus stability of the detergent compositions and/or performance may still desirably be improved.
DE-A-4009532 discloses a cleaning composition formed from two detergent pastes. One paste comprises the enzyme, zeolite A builder and other bleach sensitive ingredients and the other paste comprises perborate monohydrate builder.
EP-A-976820 discloses three layered tablets wherein the external layers comprise the enzyme system and the central layer comprises a bleaching system. The layer comprising the enzyme system may also comprise a builder.
Despite the above, there is still a need to improve enzyme stability in detergent compositions comprising an enzyme, a bleaching compound and certain organic builders.
It is an object of the present invention to address one or more of the above-mentioned problems. In particular, it is an object of the present invention to provide detergent compositions exhibiting good enzyme stability. It is a further object of the present invention to provide detergent compositions exhibiting good performance. It is still a further object of the present invention to provide detergent compositions exhibiting good enzyme stability and performance.